arm64: Inform user if software PAN is in use

It isn't entirely obvious if we're using software PAN because we
don't say anything about it in the boot log. But if we're using
hardware PAN we'll print a nice CPU feature message indicating
it. Add a print for software PAN too so we know if it's being
used or not.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9f4491d..a113113 100644 (file)
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1276,6 +1276,9 @@ static void verify_local_cpu_capabilities(void)
 
        if (system_supports_sve())
                verify_sve_features();
+
+       if (system_uses_ttbr0_pan())
+               pr_info("Emulating Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
 }
 
 void check_local_cpu_capabilities(void)